package com.headfirst.strategy.version1;

/**
 * @author sunhongguang
 * @create 2022-01-09-21:07
 */
public abstract class Duck {

    public void quack(){
        System.out.println("呱呱呱...");
    }

    public void swim(){
        System.out.println("游泳...");
    }

    public void fly(){
        System.out.println("飞翔...");
    }

    public abstract void display();
}
